United States: Tularemia, also termed “rabbit fever” or “deer fly fever,” is a seldom-encountered illness within the United States. Between 2011 and 2022, the Centers for Disease Control and Prevention (CDC) documented 2,462 occurrences of this condition across 47 states.
Notably, human infections have emerged in every state, barring Hawaii, with rural locales in Arkansas, Missouri, Oklahoma, and Kansas bearing a heightened prevalence. This disease predominantly manifests from May to September, with a pronounced incidence among children, particularly young males, according to Live Science.
Etiological Culprit
The root cause of tularemia is the bacterium Francisella tularensis, a microorganism renowned for its extraordinary infectiousness. It thrives across the Northern Hemisphere, occasionally extending its reach to tropical and southern regions.
There exist four subspecies of F. tularensis, each distinct in its geographical niche and capacity to induce severe pathology. Type A, the most virulent variant, is confined to North America. True to its epithet, tularemia predominantly afflicts animals like rabbits, hares, and rodents. However, humans can contract the disease through several pathways, including tick or deer fly bites, ingestion of tainted water, or direct interaction with infected creatures, such as through bites or handling. Alarmingly, as few as 10 to 25 bacterial cells can trigger an infection in humans.
Tularemia does not propagate via human-to-human transmission. Individuals engaging in pursuits like hunting, wildlife management, hiking, or camping are at elevated risk compared to the general populace, as per Live Science.
Clinical Manifestations
The symptoms of tularemia are contingent on the route of bacterial entry. A hallmark feature is fever, which can escalate to 104°F (40°C).
When the bacteria invade through the skin, afflicted individuals may develop a lesion at the injection site, coupled with swollen lymph nodes, particularly in the armpits or groin. Ingesting food or water contaminated with F. tularensis may provoke a sore throat, oral ulcers, or tonsillitis.
The gravest form of the disease arises when airborne F. tularensis particles are inhaled, leading to pulmonary symptoms such as chest discomfort, coughing, and breathing difficulties. These respiratory complications can also surface if untreated bacteria spread systemically to the lungs, according to Live Science.
Therapeutic Interventions
Broad-spectrum antibiotics serve as the cornerstone of tularemia treatment, significantly reducing the mortality rate from 5 percent -15 percent to approximately 2 percent. Despite this advancement, no vaccine against tularemia has been approved for use within the United States.
To mitigate the risk of infection, the CDC advises employing insect repellents during outdoor activities and wearing protective gloves when handling sick or deceased animals.